Clarify individual tasks, pair cases and cohort assignments

[zhongnz]

Problem and result

Students could mistake class-wide “Group” issues for their pair's tasks and create duplicate submissions for each milestone. Explain two student-created issue types: one Pair case for the semester and one-owner Individual tasks for meaningful contributions. Rename the maintainer template to Cohort goal and explain where personal tasks belong, how partners share artifacts, and how to request review or update a case without edit permissions.

The student guide, README, forms and contributor instructions now use the same terms. Add an example of a pair dividing work, plain-language assessment-category descriptions and completion guidance. Existing evidence and the tentative 75% individual / 25% pair scheme remain valid.

Completed live issue alignment

Updated and read back all 13 existing cohort/course issues (#1–#9, #21–#24): student actions and submission destinations come first; shared goals use [Cohort] titles; pair checkpoints stay in each Pair case. Preserve assessment mapping, research criteria, working targets and previous contribution references. Verified issue states, owners, labels and milestone assignments were preserved. Student-authored #28/#30 and historical issues were not edited.

Validation

• Local documentation links/anchors, issue-form YAML and current grading arithmetic pass.
• Checked all 13 proposed issue bodies for resource links, task destinations, assessment mapping and preserved student references.
• git diff --check passes. Required CI passed on Python 3.11/3.13 before merge; experiment code is unchanged.

Merge handling

The repository owner remains the only eligible reviewer. Used the documented owner bootstrap exception after required checks passed on a9bebed500bfff08c73b50cea4e6cdc72cbeb673. No independent approval is claimed and announced course policy is unchanged.

Merged main at 670e5af197038999a9ec58c11d5be574020fd08b also passed CI. Local main is clean and synchronized.